The subject invention relates to a one piece plastic binding strap or cable tie which comprising a stop head part and a ladder-like band part. The head part has a passage opening with an internal holding projection adapted to engage in the profile of the band part. Lying opposite the holding projection is a guide element provided with a guide track for the band part.
Broadly, such a binding strap is known in the prior art. U.S. Pat. No. 3,488,813 shows a strap in which a holding projection is formed in the lower zone of the head part. The upper zone of the holding projection, in the band introduction direction, lies against an oblique surface in the head part and is pressed back in the opposite direction during the introduction of the band to be held. The guide track lies opposite the holding projection and is arched in the beginning zone and directly joins to an oblique track section. In this structure, only the portion of the holding projection projecting into the guide channel is effective in holding the band. The band part, during the mounting and during the holding, remains in the same plane in the head part. The use of this binder requires some skill because of its elaborate structure.
The prior art also includes a binder strap with a guide channel passing through a head, which has two side channels, lying opposite each other. See, for example, West German Patent No. 2,328,955. In the closed position, through the action of the band part, the elastic holding projection is pressed against a back wall of a side channel, by which the closing position is effected. This known construction is elaborate to build and requires, for the holding of the band part, the contact of the holding projection against the wall of a side channel. Thus, a pull on the strap must constantly be present in order to assure the maintenance of the closing position.
U.S. Pat. No. 4,001,898 shows a band element which is so designed that the holding projection is a rigid element, which in the passage direction lies opposite an elastic guide element. Here, the holding projection and the guide element have the same width. In introducing the band part into the passage opening, the elastic guide element is first pressed back until the band part lies, in the closed position, against the rear zone of the rigid holding projection. The guide element in this known construction can swing and has, to its disadvantage, a weak place precisely in the swinging zone. Thus, the life of this known construction is considerably reduced. Moreover, the band part is only partially guided during the mounting, so that again, some skill is required to carry out a perfect mounting.